JP5159361B2 - interchangeable lens - Google Patents

Description

  The present invention relates to an interchangeable lens that sends aberration correction data suitable for digital aberration correction to a camera body in accordance with the model of the camera body.

  In a camera system such as a color electronic still camera or video camera, a color image is reproduced by superimposing images of an R (red) channel, a G (green) channel, and a B (blue) channel. When the subject image is formed on the image sensor through the lens, registration errors and distortion occur. One of the causes is lens aberration, particularly lateral chromatic aberration and distortion.

  Various methods have been proposed for electrically correcting lateral chromatic aberration and distortion. For example, Patent Document 1 discloses the arrangement of pixel outputs of color components that cause registration errors, that is, color matching errors of each channel. A correction method to be changed has been proposed.

  Patent Document 2 discloses a camera device for identifying the lens number and model and reading the correct correction data according to the lens number and model for the data transfer method of the interchangeable lens type electronic still camera and video camera. Has been proposed.

Furthermore, Patent Document 3 discloses a camera that uses a lens with a built-in extender function, and changes the distortion correction amount (distortion correction amount) when the lens extender is used or not used.
JP 2000-138944 A Japanese Patent Laid-Open No. 61-225988 Japanese Patent Laid-Open No. 62-194787

  As in Patent Documents 2 and 3, in a system in which correction data is changed according to the type of lens and usage status, the correction data sent by the lens is changed or the camera body has correction in accordance with the change of the optical system. The correction data to be used is selected from the data. However, it is not assumed that one interchangeable lens is attached to a plurality of different camera bodies, such as a broadcast lens, or is attached to a camera body in a different shooting situation or shooting mode.

  In addition, there are cases where the required resolution for broadcast cameras is different for HD (high definition), SD (standard definition), or cinema. On the other hand, FIG. 16 shows the lateral chromatic aberration of the camera characteristics A and B. Depending on different modes and camera types, different color characteristics may be obtained even if the same lens is used. Therefore, in the broadcast imaging system, it is necessary to consider the case where the same lens is attached to a different type of camera, or the case where the same type of camera is used for shooting in different shooting situations or different shooting modes.

  An object of the present invention is to provide an interchangeable lens capable of solving such problems of the prior art and performing optimum aberration correction according to various situations.

In order to achieve the above object, an interchangeable lens according to the present invention is an interchangeable lens that can be attached to and detached from a camera body, and receives from the camera body information related to the type of the camera body, and the receiver receives the information. A transmission unit that transmits aberration correction data including data relating to the amount of chromatic aberration of magnification based on the obtained information to the camera body, and the aberration correction data has an influence of the chromatic aberration of magnification on an image captured by the camera body. Data used for image processing for reducing image data, wherein the transmission unit transmits different aberration correction data to the camera body according to information on the type of the camera body received by the reception unit. It is a feature.

  According to the interchangeable lens according to the present invention, since appropriate data can be transmitted from the interchangeable lens to the camera body according to the situation, a clear image with small aberration can be obtained on the camera side.

  In the interchangeable lens of this embodiment (especially an interchangeable lens for broadcasting equipment and a photographing optical system), the same lens is mounted on a different type of camera, or is photographed in different photographing modes under different photographing conditions (with different light sources). It is necessary to consider the case of mounting on the (identical) camera. In the present embodiment, when the same interchangeable lens is attached to a different type of camera, or attached to a camera that shoots in a different shooting situation or in a different shooting mode, the amount (size) of magnification chromatic aberration to be considered is The point is to change. In other words, the interchangeable lens of this embodiment is transmitted from the interchangeable lens to the camera body when it is attached to a camera with a different shooting environment (different types of cameras, different shooting conditions, and different shooting modes) as described above. The data about interchangeable lenses is changing. In this embodiment, the camera body is a color separation optical system that separates the photographing light received from the photographing lens (interchangeable lens) into red (R), green (G), and blue (B) color lights. (Prism) and an image sensor corresponding to each color light (not shown). When chromatic aberration of magnification occurs in the present embodiment, the size, distortion method, and distortion amount of images formed on the respective image sensors differ, and color is generated when a color image is created by combining three color images. May appear blurred. In this embodiment, even in a situation where chromatic aberration of magnification occurs in this way, the image is corrected (corrected) digitally (by image processing) in order to obtain a color image with no (or less) color blurring. Appropriate data necessary for digitally correcting an image (data relating to chromatic aberration of magnification, data relating to distortion for each color light) is transmitted from the interchangeable lens side to the camera body.

  In this embodiment, the data relating to the interchangeable lens is data relating to lateral chromatic aberration (other aberrations) (particularly data relating to aberrations that vary depending on the wavelength), data for correcting the aberrations, and the like. Also, different types of cameras are different in resolution (such as HD cameras and SD cameras as described above) and different types of signals (data formats) that can be received by different manufacturers. It is a camera. Also, different shooting situations include shooting under sunlight (outdoor shooting), shooting under electric light (indoor shooting), shooting in the dark (night view shooting), and saturation (signal saturation). It is a situation that occurs. In other words, the shooting situation is the spectral intensity (luminance distribution) of the light that illuminates the subject. In this embodiment, the spectral intensity is based on the light incident on the image sensor, AF sensor, and other luminance sensors. Detected (judged). In addition, as described above, different shooting modes refer to indoor shooting mode, outdoor shooting mode, night scene shooting mode, shooting mode under conditions where saturation occurs (shooting mode to prevent saturation), etc. Yes.

  In addition, the type of camera body, shooting conditions, shooting mode, etc. may be determined through transmission / reception of signals to / from the camera body, or based on the detection result of a sensor provided on the interchangeable lens body. Alternatively, the determination may be made based on manual input by the photographer. The sensor referred to here is, for example, a luminance sensor for determining a shooting situation, and originally detects light emitted from a light source that illuminates the subject (the luminance sensor provided in or near the subject is used to detect light). It is desirable to detect the spectrum). However, since it is difficult to actually arrange the luminance sensor in the subject or in the vicinity thereof, the luminance sensor may be provided on the interchangeable lens (exterior), the camera main body (exterior), or You may provide in the position into which a part of imaging | photography light in an optical system injects. Of course, as in Example 7 to be described later, the photographing situation may be determined based on the luminance distribution (spectral intensity) of the photographing light received by the image sensors 101 and 60.

  The interchangeable lens of the present embodiment is based on at least one of the data received from the camera body, the detection result of the detector (sensor) provided in the interchangeable lens, and the input signal input to the interchangeable lens. Change the data sent to the camera body. Here, the functions to receive information about the shooting environment, identify the shooting environment (spectral intensity of the light source that illuminates the subject, shooting mode, camera type), and send data from the interchangeable lens to the camera body The same arithmetic circuit (CPU) in the interchangeable lens takes charge. However, these functions (a function as a reception unit, a function as an imaging environment identification unit, and a function as a transmission unit) may be performed by separate arithmetic circuits. The receiving unit may receive various information from the camera body side, and a sensor (such as a light receiving sensor for AF, a luminance sensor provided on the exterior of the interchangeable lens, or the like) disposed on the interchangeable lens. , A detection signal of a light receiving sensor that receives light) may be received.

  By configuring as described above, it is possible to send appropriate data (aberration correction data) to the camera body according to the camera used, or the environment (shooting conditions) used, the shooting mode, etc. A high-quality image can be obtained by performing proper aberration correction. The aberration correction data referred to here is an image of each color (specifically, a red, green, and blue image) that is distorted digitally (image) when it is distorted by the influence of different aberrations. Data used to correct (correct) (in processing). That is, it is data indicating (or relating to) how much the image of each color is distorted.

  As can be understood from the contents described above and the contents specifically described below, in this embodiment, when the photographing environment is different, the aberration correction data transmitted from the interchangeable lens to the camera body is necessarily different. Of course, the same aberration correction data may be transmitted even in different shooting environments, but this is an exception.

  Hereinafter, a specific example of the present embodiment will be described in detail with reference to FIGS.

  FIG. 1 is a configuration diagram of the photographing apparatus according to the first embodiment. The interchangeable lens 1 is detachably attached to the camera body 100. The interchangeable lens 1 includes a focus lens (focus lens unit) 2, a zoom lens (zoom lens unit, variable power lens unit) 3, and a diaphragm (light quantity adjustment unit) 4 on the optical axis. The positions of the focus lens 2, the zoom lens 3, and the diaphragm 4 are detected by a focus position detection device 11, a zoom position detection device 12, and a diaphragm position detection device 13, respectively. The optical system parameters to be described later are information on the current position of the focus lens 2 and the zoom lens 3, information on the focal length, aperture value of the aperture 4 (a value indicating the degree of opening of the aperture, an aperture diameter), and the like. It is sufficient if at least one is included. Note that these components are preferably arranged in this order from the subject lens (object side) toward the image sensor 101 that forms the subject image, in the order of the focus lens 2, the zoom lens 3, and the diaphragm 4. May be different.

  Outputs of these position detection devices 11 to 13 are connected to an optical system parameter acquisition unit 21 in an arithmetic circuit 20 composed of a CPU or the like, and an output of the optical system parameter acquisition unit 21 is connected to a camera body identification unit 22. . The camera body identification unit 22 is connected to a characteristic data reception unit 23, a transmission type conversion unit 24, and a correction data memory 25 outside the arithmetic circuit 20.

  The characteristic data receiving unit 23 is connected to the camera body 100 side, and the sending type conversion unit 24 is connected to the camera body 100 side via the correction data transmitting unit 26. The correction data memory 25 stores distortion correction data in RGB of the optical system.

  In the camera body 100, an image sensor 101 is provided on the image side of a subject that has passed through the focus lens 2 of the interchangeable lens 1, and the output of the image sensor 101 is connected to a correction coordinate calculation unit 103 in an arithmetic circuit 102 composed of a CPU or the like. ing. The output of the correction coordinate calculation unit 103 is connected to a correction data receiving unit 104 that receives correction data from the interchangeable lens 1 and a data interpolation processing unit 105. Further, the output of the data interpolation processing unit 105 is connected to a signal output means 106 outside the arithmetic circuit 102, and the output of the signal output means 106 is further connected to a recording medium 107 outside the camera body 100.

  In addition, a characteristic data memory 109 outside the arithmetic circuit 102 is connected to the characteristic data transmission unit 108 that transmits characteristic data to the interchangeable lens 1 in the arithmetic circuit 102, and the characteristic data memory 109 is the characteristic data of the camera body 100. Is remembered. The recording medium 107 is outside the camera body 100, but may be provided inside.

  FIG. 2 is a process flowchart for correcting a captured image by the camera body 100 having the interchangeable lens 1 shown in FIG. First, the interchangeable lens 1 is powered on and initialized (step S10). At the same time as the initialization is completed, the position detection devices 11 to 13 send the optical system parameters of the focus lens 2, the zoom lens 3, and the diaphragm 4 to the optical system parameter acquisition unit 21. The information received by the optical system parameter acquisition unit 21 is sent to the camera body identification unit 22 to grasp the initial state of the optical system. (Step S20).

  Next, if the interchangeable lens 1 calls the camera body 100 and there is a response, communication is established and the processing proceeds to the subsequent processing. However, if there is no response to several calls, the camera body 100 cannot communicate. It is determined that there is, and the subsequent processing is stopped (step S30). Simultaneously with the confirmation of communication establishment, the characteristic data transmission unit 108 reads the characteristic data from the characteristic data memory 109 of the camera body 100 and transmits it to the interchangeable lens 1. This data is received by the characteristic data receiving unit 23 of the interchangeable lens 1 and sent to the camera body identifying unit 22 (step S40).

  The camera body identification unit 22 identifies the model of the camera body 100 based on the characteristic data (steps S50 and S60). When the type is applied to the registered type A or type B, the data corresponding to the optical system parameter acquired in step S20 or data in the vicinity is read from the correction data memory 25 for each type of data. (Steps S51 and S61).

  At this time, if not in the registration type, the design value data is applied as it is (step S62). The data read in steps S51, S61, and S62 is sent to the transmission type conversion unit 24, and the data type and the transfer type are converted for each type of the camera body 100. Then, the converted data is transmitted to the correction data receiving unit 104 of the camera body 100 via the correction data transmitting unit 26 (step S90).

  On the other hand, the subject image photographed by the camera body 100 is imaged on the image sensor 101 through an optical system such as the focus lens 2, and is output as image data and sent to the correction coordinate calculation unit 103 (step S100). The correction coordinate calculation unit 103 receives the correction data from the correction data receiving unit 104, and the image data sent from the image sensor 101 is divided into position data and luminance data for each RGB channel. Then, the RGB coordinate data correction values are calculated using the correction data and the position data of each channel (step S110). At this time, since the position coordinates after correction partially overlap and partly blank, a data interpolation processing unit 105 performs interpolation processing (step S120). The image data after data interpolation is sent to the signal output means 106 and written to the recording medium 107 (step S130). Alternatively, when imaging in real time, the video is directly output from the signal output means 106.

  In addition, since the process of above-mentioned step S20-S130 is performed for every image, step S20-S130 will be repeated for every frame. In addition, intermediate communication establishment and confirmation of the type of the camera body 100 may be omitted as appropriate without being performed each time.

  FIG. 3 shows an example of a correction data storage method in the correction data memory 25 used in steps S51, S61, and S62, and the data is stored as a table. The table shows the distortion correction amount of the G channel with respect to zoom and image height change at a position f of a certain focus lens 2 and a position i of the diaphragm 4.

  The vertical axis indicates the zoom direction, the upper side indicates the wide-angle direction, the lower side indicates the telephoto direction, the horizontal axis indicates the image height from the optical axis, the left side is near the optical axis, and the distance from the optical axis increases toward the right side.

  For this reason, it is necessary to prepare at least two similar tables for the R channel and the B channel at least. If there are multiple data in the focus direction (closest to infinity) and the aperture direction (open to close), that amount Will also have a table. The distortion correction amount is generally about 12% at maximum with respect to the field of view. If the HD resolution is 1920/1080 pixels, the correction amount is slightly more than 130 pixels, so it is usually appropriate to configure a table with 2 bytes of data. Correction is possible.

  FIG. 4 also shows an example of the correction data storage method used in steps S51, S61, and S62 as in FIG. 3, and the data is stored as coefficients. The distortion correction amount in the image height direction is indicated by a pair of coefficients, the vertical axis indicates the zoom direction, and the correction amount in the zoom / image height direction for all the RGB channels can be obtained with this one table. .

  In FIG. 4, the correction amount in the image height direction has a coefficient represented by a quadratic function, and the correction amount in each RGB channel at an arbitrary image height h using A to F in the following equation (1). ΔR, ΔG, and ΔB can be calculated.

  These two types of tables can be converted to each other, and in order to convert from the type of FIG. 3 to the type of FIG. 4, the table in the image height direction of FIG. 3 is used, and fitting is performed using the least square method or the like. Can be converted into two coefficients as shown in equation (1). On the other hand, in order to convert from the model shown in FIG. 4 to the model shown in FIG. 3, the image height h can be input to the formula (1) to convert it into a correction amount.

  Therefore, if any one type of table is provided and the interchangeable lens 1 includes the arithmetic circuit 20 for converting the model, the camera body 100 can cope with any type of data. It becomes possible. In FIG. 1, the transmission type conversion unit 24 of the arithmetic circuit 20 plays this role.

  In addition, since the transfer type may be different for each camera body 100, it is necessary to convert the data to a transfer type corresponding to a format unique to the camera body 100 in addition to a general type such as RS-232C. is there. In FIG. 1, this transfer type conversion is also performed in the transmission type conversion unit 24 simultaneously with the above data type change.

  With respect to the table in FIG. 4, a method of expressing not only the image height direction but also the data in the zoom direction with one expression is also conceivable. For example, as shown in Expression (2), an arbitrary image height h and an arbitrary zoom z are used. It can also be expressed as

  In this case, since it is not necessary to have table data corresponding to the zoom direction, the number of table data can be further reduced, but the calculation time increases.

  In FIG. 3, one table is provided for the zoom / image height direction in which the variation of the chromatic aberration of magnification is relatively large. However, when the amount of data is excessive and excessive correction, the data in the image height direction is reduced, It becomes possible to improve the processing speed. Depending on the type of optical system, there is no problem even if a table is formed in the focus / aperture direction. Further, although a quadratic function is used in FIG. 4, it is possible to obtain a correction value with higher accuracy by expressing it using a higher order function.

  FIG. 5 shows a configuration diagram of the second embodiment, and the same reference numerals as those in FIG. 1 denote the same members. An extender lens 5 is detachably added on the optical axis, and an extender insertion / removal detection device 14 for detecting the insertion / removal of the extender lens 5 is provided. Connected to the unit 21.

  The output of the optical system parameter acquisition unit 21 is connected to the SD / HD identification unit 31, and the output of the SD / HD identification unit 31 is connected to the characteristic data reception unit 23, 2 → 1 byte conversion unit 42, and linear approximation processing unit 43. The output of the linear approximation processing unit 43 is connected to the sending type conversion unit 24.

  In the camera body 100, an SD / HD memory 111 storing whether the camera body 100 is SD compatible or HD compatible is connected to the characteristic data transmission unit 108.

  FIG. 6 is a process flowchart of the second embodiment. First, initialization is performed when the interchangeable lens 1 is powered on (step S10). Simultaneously with the end of the initialization, the optical system parameter acquisition unit 21 acquires the focus lens 2, the zoom lens 3, the aperture 4 position, and the insertion / removal parameters of the extender lens 5 from each of the detection devices 11 to 14 (step S21).

  Next, when the interchangeable lens 1 calls the camera body 100 and there is a response and communication is established (step S30), the characteristic data transmission unit 108 determines whether the camera body 100 is SD compatible or HD compatible from the SD / HD memory 111. Is transmitted to the interchangeable lens 1. The characteristic data receiving unit 23 of the interchangeable lens 1 receives the data and sends it to the SD / HD identifying unit 41 (step S40).

  The SD / HD identifying unit 41 identifies whether the camera body 100 is SD compatible or HD compatible from the received data (step S55). If the camera body 100 is SD, the permissible circle of confusion is about twice that of HD. Accordingly, the correction data memory thins out the data in the image height direction at a pitch that can be sufficiently corrected for the resolution of the SD pixel size of 10 μm from the correction data that matches or is close to the optical system parameter acquired in step S21. 25 is read (step S56). The read data is sent to the 2 → 1 byte conversion unit 42, compressed to 1/256 (truncated after the decimal point), and then sent to the transmission type conversion unit 24 (step S57).

  On the other hand, if it is HD compatible, it has a high resolution of a pixel size of 5 μm compared to SD, and the allowable circle of confusion is reduced to about half compared to SD. Accordingly, data at all image heights are read for correction data that matches or is close to the optical system parameter acquired in step S20 (step S66). Even when SD or HD cannot be discriminated, all image height data is read in the same way as HD. The read data is sent to the linear approximation processing unit 43, subjected to linear approximation processing, and then sent to the sending type conversion unit 24 (step S67).

  The data sent to the sending type conversion unit 24 is changed to the data type required by the camera body 100 and transmitted to the correction data receiving unit 104 via the correction data sending unit 26 (step S90).

  Processing steps S100 to S130 in the camera body 100 are the same as those in the flowchart of FIG.

  FIG. 7 is an explanatory diagram of the linear approximation process in step S67, and shows a part of the data shown in FIG. The zoom / image height position of the optical system parameter acquired by the optical system parameter acquisition unit 21 indicates ☆, and when there is no matching data in the table, there are four adjacent a, b, c, and d. Calculate the value of ☆ from the linear approximation using the value.

  First, a case is considered in which the number of divisions between each data necessary to sufficiently satisfy the required accuracy is determined in advance, and it is necessary to divide the data into n pieces in the zoom direction and m pieces in the image height direction. As the previous stage of calculating the value of ☆, since k is the kth in the image height direction, the kth data ○ obtained by dividing a to c into n and the kth data obtained by dividing b through d into n Data △ is calculated. The calculation formula is as shown in the following formula (3) and formula (4).

  Next, since ☆ is the l-th in the zoom direction, the value of ☆ is obtained by calculating the l-th data obtained by dividing ◯ to Δ into m. The calculation formula is as shown in the following formula (5).

  FIG. 8 is an explanatory diagram of the linear approximation process in step S67 of FIG. 6, but shows the concept of data between tables, not between data in one table as shown in FIG. This concept is the same for both focus and aperture.

  The position of the optical system parameter acquired by the optical system parameter acquisition unit 21 indicates ☆, and when there is no matching table, the neighboring A table and B table are used to calculate the value of ☆ from linear approximation. . If the zoom / image height position in the A table corresponding to the zoom / image height of ☆ is ×, and the zoom / image height position in the B table is ●, then ☆ is calculated from linear approximation using × and ●. It is possible.

  The number of divisions between the tables sufficiently satisfying the required accuracy is n, and the calculation formula for calculating ☆ when the table including ☆ is kth is as shown in the following formula (6). It is.

  By this equation (6), it is possible to calculate values in three parameters including information on either the focus or the diaphragm in addition to the zoom and image height. Using this method, it is possible to calculate values satisfying all four parameters by repeatedly performing the same calculation for the focus or the aperture.

  Since linear approximation processing is not essential, if the number of data divisions or the number of tables is increased in order to guarantee the required accuracy, more memory capacity is required but less calculation processing is required. Depending on the case, the linear approximation process may be omitted. In the second embodiment, the linear approximation process is performed in the interchangeable lens 1, but the same effect can be obtained even if it is performed in the camera body 100.

  FIG. 9 is a configuration diagram of the third embodiment, and the same reference numerals as those in FIGS. 1 and 5 denote the same members. Outputs of the optical system parameter acquisition unit 21 that acquires the positions of the focus position detection device 11, the zoom position detection device 12, and the aperture position detection device 13 are connected to a mode identification unit 51. The mode identification unit 51 is connected to the output of a mode switching device 52 composed of a switch or the like. The characteristic data receiving unit 23 is omitted, and the characteristic data transmitting unit 108 is also omitted in the camera body 100.

  FIG. 10 is a process flowchart of the third embodiment. Steps S10 to S30 are the same as those in the flowchart of FIG. After the communication is established in step S30, the mode identification unit 51 reads the mode information set by the mode switching device 52 and confirms the current mode (step S41). First, it is determined whether or not the mode is the high-definition mode (step S70). When it is determined that the mode is the high-definition mode, correction data that matches or is close to the optical system parameter acquired in step S20 is read ( Step S74).

  If not in the high-definition mode, the image height component data is thinned out and read at a value that matches or is close to the optical system parameter acquired in step S20 (step S71). Next, the presence / absence of linear approximation is determined (step S72). In the case of performing linear approximation, the read data is sent to the linear approximation processing unit 43 to perform linear approximation processing (step S75).

  Next, the presence / absence of data compression is determined (step S73). In the case of data compression, the data is sent to the 2 → 1 byte conversion unit 42 and compressed to 1/256 (truncated after the decimal point) (step S76). Those subjected to linear approximation processing or data compression are sent to the transmission type conversion unit 24 after processing. When these processes are not performed, the data is sent to the transmission type conversion unit 24 without passing through the linear approximation processing unit 43 or the 2 → 1 byte conversion unit 42. Then, after being converted into a data type for transfer, the data is transmitted to the correction data receiving unit 104 via the correction data transmitting unit 26 (step S90).

  Further, the processing of steps S100 to S130 in the camera body 100 is the same as that in the flowchart of FIG.

  FIG. 11 is a configuration diagram of the fourth embodiment, and the same reference numerals as those in FIGS. 1, 5, and 9 denote the same members. A mode reception unit 61 is connected to the mode identification unit 51, and the mode reception unit 61 is connected to a mode transmission unit 121 of the camera body 100. A mode switching device 122 is connected to the mode transmission unit 121 of the camera body 100.

  FIG. 12 is a process flowchart of the fourth embodiment, and steps S10 to S30 are the same as the flowchart of FIG. After the communication is established in step S30, in the camera body 100, the mode transmission unit 121 reads the mode switching request set by the mode switching device 122, and is sent to the mode identification unit 51 via the mode reception unit 61 of the interchangeable lens 1. The mode is confirmed (step S41). Steps S70 to S90 are the same as those in the flowchart of FIG.

  The subject image captured by the camera body 100 is imaged on the image sensor 101 through the optical system, output as image data, and sent to the correction coordinate calculation unit 103 (step S100). The correction coordinate calculation unit 103 receives the correction data from the correction data receiving unit 104, and the image data sent from the image sensor 101 is divided into position data and luminance data for each RGB channel. Then, using the correction data and the position data of each channel, RGB coordinate data correction values are calculated. At this time, since the correction data is data of lateral chromatic aberration, each correction value is expressed as a relative value with respect to the G channel. Accordingly, the position coordinates of the R channel and the B channel are corrected as relative values with respect to the position data of the G channel image (step S110). Then, the data interpolation processing unit 105 performs an interpolation process (step S120).

  The image data after the data interpolation is sent to the signal output means 106, and the signal output means 106 transmits the signal to the recording medium 107 and writes it in the recording medium 107 (step S130).

  FIG. 13 is a configuration diagram of the fifth embodiment, and the same reference numerals as those of the third embodiment in FIG. 9 denote the same members. A magnification chromatic aberration extraction unit 71 is interposed between the mode identification unit 51 and the 2 → 1 byte conversion unit 42.

  As shown in FIG. 14, the order of correction of the lateral chromatic aberration and the distortion is different. Therefore, in order to correct the distortion, it is considered that data of 2 bytes is usually required for HD as described above in the second embodiment. . On the other hand, the chromatic aberration of magnification is generally about 30 μm at the maximum, and considering the HD resolution of 1920 × 1080 pixels, the correction amount is only about 6 pixels, and 1 byte of data is sufficient. In order to reduce the amount of data, the mode switching device 52 is provided with a mode switching function for separating and processing magnification chromatic aberration and distortion.

  The above-described processing method is transmitted from the mode switching device 52 to the mode identifying unit 51 to determine the processing method. On the other hand, the position detection devices 11 to 13 send optical system parameters of focus, zoom, and stop to the optical system parameter acquisition unit 21 to grasp the initial state of the optical system.

  Based on the optical system parameter values, the mode identifying unit 51 reads desired data in the optical system parameters. When only the lateral chromatic aberration is corrected, it is sent to the lateral chromatic aberration extracting unit 71 and converted into ΔR ′ and ΔB ′ by the following equation (7).

  Since this data has an excessive pitch with respect to the correction accuracy, the data is sent to the 2 → 1 byte conversion unit 42 for data compression. In order to reduce the amount of data, it may be considered that data is sent to the camera body 100 in the form of chromatic aberration of magnification of the R channel and B channel with respect to the distortion of the G channel. At that time, the G channel data is sent as usual, whereas the R channel and B channel data is extracted and compressed in the same manner as described above and sent to the camera body 100. When sending to the camera body 100, the sending type conversion unit 24 converts the data to a transfer data type as in the first to third embodiments, and the correction data transmission unit 26 transmits the data to the correction data reception unit 104.

  The lateral chromatic aberration of the R channel and the B channel can be considered as a difference value between the distortion of the R channel and the B channel with respect to the distortion of the G channel. Therefore, when you have only distortion amount. When all colors are used as the amount of distortion. When the distortion amount of the G channel and the magnification chromatic aberration amount of the R channel / B channel with respect to the G channel are provided. In addition, four types of cases where only the lateral chromatic aberration of the R channel and the B channel are assumed are assumed.

  FIG. 15 is a process flowchart of the fifth embodiment. Steps S10 to S41 are the same as those in the flowchart of FIG.

  First, it is determined whether or not it is a mode for correcting only lateral chromatic aberration (step S80). In the mode for correcting only the lateral chromatic aberration, correction data that matches or is close to the optical system parameter acquired in step S20 is read (step S83). The magnification chromatic aberration extraction unit 71 calculates the difference value between the R channel and the B channel with respect to the G channel (step S84), the data is compressed by the 2 → 1 byte conversion unit 42, and is sent to the transmission type conversion unit 24 (step S85).

  In the mode for correcting not only the lateral chromatic aberration but also the distortion, first, similarly to the above, first, correction data matching or near the optical system parameter acquired in step S20 is read (step S81). Next, it is determined whether or not only the chromatic aberration of magnification is compressed in order to compress the data (step S82). When compressing only the lateral chromatic aberration, the lateral chromatic aberration extracting unit 71 extracts the R channel and the B channel as a difference from the G channel distortion (step S84). The R channel and the B channel are compressed by the 2 → 1 byte conversion unit 42 and sent to the transmission type conversion unit 24 (step S85). At this time, the G channel is sent directly to the transmission type conversion unit 24 without passing through the magnification chromatic aberration extraction unit 71 or the 2 → 1 byte conversion unit 42.

  In a mode in which no processing is performed, all the components of the R channel, the G channel, and the B channel are sent out without passing through the magnification chromatic aberration extracting unit 71 and the 2 → 1 byte converting unit 42. Send directly to section 24. The data sent to the sending type conversion unit 24 is converted into a data type for transfer, and then transmitted to the correction data receiving unit 104 via the correction data sending unit 26 (step S90).

  Moreover, the process of step S100-S130 is the same as that of the flowchart figure of FIG.

  Example 6 will be described. The difference in shooting situation in the sixth embodiment is a difference in spectral intensity (luminance distribution) of light emitted from a light source that illuminates a subject. What is actually detected (measured) is the spectral intensity (luminance distribution) of light incident on a sensor provided in the imaging device or the interchangeable lens for imaging, and the difference in the detection result is the difference in the imaging situation.

  A specific example is shown in FIG. In FIG. 17, “3200K” indicates the luminance distribution of electric light (color temperature is 3200K), “5600K” indicates the luminance distribution of sunlight (color temperature is 5600K), and “fluorescent lamp” indicates the luminance distribution of the fluorescent lamp. ing. Here, sunlight (color temperature 5600K) has a relatively flat spectrum with respect to other light sources, but electric light (color temperature 3200K) increases in spectral intensity toward the longer wavelength side. Have such a spectrum. Therefore, the center wavelength (center of gravity wavelength) of each color when photographing under electric light is shifted compared to the center wavelength (center of gravity wavelength) of each color (red, green, blue, etc.) when photographing under sunlight. For this reason, the influence of the lateral chromatic aberration on the image changes as compared with photographing under sunlight. In addition, when shooting under light having an emission line spectrum that has a peak with extremely high spectral intensity, such as a fluorescent lamp, the center wavelength (center of gravity wavelength) of the color light that includes that peak shifts. The effect of the chromatic aberration of magnification on the image changes as compared to shooting under sunlight.

  In addition, as the case where the influence of the magnification color change on the image changes, the following cases are assumed.

  When the characteristics of optical elements (filters, prisms, etc.) for blocking infrared light or ultraviolet light in the interchangeable lens (so that they do not enter the image sensor) change the wavelength range of red light and blue light. . That is, the wavelength region of each color light changes depending on the characteristics of the optical element for shielding infrared light and ultraviolet light, and as a result, the center wavelength (center of gravity wavelength) of each color light changes. If the wavelength region of red light and blue light changes, the center wavelength (center of gravity wavelength) of each color light changes, and as a result, the influence of magnification chromatic aberration on the image changes. In addition, it is assumed that the interchangeable lens is attached to an imaging apparatus having a color separation optical system (color separation prism or the like) that separates photographing light that has passed through the interchangeable lens into red light, green light, and blue light. If the characteristics of the color separation optical system change, the wavelength region of each color light changes. If the wavelength region of each color light changes, the center wavelength (centroid wavelength) of each color light changes, and as a result, the influence of the lateral chromatic aberration on the image changes.

  Here, the influence of lateral chromatic aberration on the image changes. For example, in photographing under sunlight, light in a wavelength region that has lateral chromatic aberration but did not significantly adversely affect image quality is given to the image. It means that the impact will be greater. For example, since the photographing situation (spectral intensity of light irradiated to the subject) has changed and the spectral intensity in the above-mentioned wavelength region has become very high, there is a case where an adverse effect due to the chromatic aberration of magnification may be seen. This situation is referred to as a change in the influence of lateral chromatic aberration on the image. This appears remarkably in, for example, reflection of mercury lamp illumination during night scene photography.

  FIG. 18 shows the amount of chromatic aberration of magnification to be corrected when the subject is illuminated with the above-mentioned electric light, sunlight, or fluorescent light. In this way, in different shooting situations (situations where shooting is performed under different light sources), it is possible to obtain images of almost the same quality even in different shooting situations by correcting different amounts of lateral chromatic aberration. Can do.

  FIG. 19 is a block diagram of the sixth embodiment. The same reference numerals as those in FIGS. 1, 5, 11, and 13 denote the same members. Outputs of the optical system parameter acquisition unit 21 for acquiring the positions of the focus position detection device 11, the zoom position detection device 12, and the iris position detection device 13 are connected to a photographing environment identification unit 81. . The shooting environment identification unit 81 is connected to the output of the shooting environment setting device 82 including a switch or the like. Based on the input of the shooting environment setting performed by the photographer or the like, the shooting environment is identified (discriminated or determined). )I do. In this embodiment, the imaging environment setting device 82 is provided in the interchangeable lens 1, but the same effect can be obtained even if it is provided in the camera body 100. Note that the shooting environment referred to here may include the shooting mode, the type of camera, and the like in addition to the shooting status, as described above.

  FIG. 20 is a process flowchart of the sixth embodiment. Steps S10 to S30 are the same as those in the flowchart of FIG. After the communication is established in step S30, the shooting environment identification unit 81 reads the shooting environment information set by the shooting environment setting device 82 and checks the current shooting environment (step S42).

  Then, based on the procedure of steps S140 to 142, it is determined what kind of environment the photographing environment is. Here, the shooting environment is described as a procedure for identifying any one of indoor, outdoor, outdoor at night (night view), and saturation (signal saturation). The environment may be identified.

  Next, appropriate correction data (data for correcting chromatic aberration of magnification) corresponding to each photographing environment is read from the correction data memory 25 (S150 to 153).

  Next, after the above-mentioned correction data is converted into a transfer data type by the transmission type conversion unit 24, it is transmitted to the correction data reception unit 104 via the correction data transmission unit 26 (step S90).

  The processes in steps S100 to S130 in the camera body 100 are the same as those in the flowchart in FIG.

  FIG. 21 is a block diagram of the seventh embodiment. The same reference numerals as those in FIGS. 1, 5, 11, 13, 19, and 21 denote the same members. A luminance information acquisition unit 131 that acquires luminance information (spectral intensity) of a video signal from the image sensor 101, a saturation region calculation unit 132 that calculates a saturation region in the screen based on the luminance information, and a color that calculates a color temperature based on the luminance information. A temperature calculation unit 133 is newly provided. Then, a shooting environment transmission unit 134 that transmits the information (related to the shooting environment) from the camera body 100 to the interchangeable lens 1 and a shooting environment reception unit 83 that receives information (related to the shooting environment) from the camera body 100 are provided. It has been.

  FIG. 21 is a process flowchart of the seventh embodiment. Steps S10 to S30 are the same as those in the flowchart of FIG. After the communication is established in step S30, the luminance information acquisition unit 131 extracts the luminance information from the video signal of the image sensor 101 in the camera body 100 (step S43). The luminance information is sent to the saturation region calculation unit 132 and the color temperature calculation unit 133, and the pixel in which the luminance is saturated and the color temperature of the shooting environment are calculated, respectively, and the information is transmitted to the shooting environment transmission unit 134 and the shooting environment reception unit 83. Then, the image is sent to the photographing environment identification unit 81 (step S43).

The photographing environment identification unit 81 first reads correction data for daylight or electric light from the correction data memory 25 with the color temperature information under the photographing environment as the bottom (steps S143 to 145). Next, saturation correction data is further read from the correction data memory 25 for the pixels in which the luminance saturation information of each pixel is saturated downward (steps S154 and 155).
Then, after being converted into a data type for transfer by the transmission type conversion unit 24, it is transmitted to the correction data receiving unit 104 via the correction data transmitting unit 26 (step S90).

  The processing in steps S100 to S130 in the camera body 100 is the same as the flowchart in FIG.

  In the seventh embodiment, the shooting environment identification unit 81 uses the input signal to the image sensor 101 (shooting light incident on the image sensor 101) to identify the shooting environment, but the present invention is not limited thereto. For example, the imaging environment may be identified using a measuring machine (luminance sensor, illuminometer, etc.) provided separately from the image sensor 101. The measuring device may be provided in the camera body 100 or the interchangeable lens 1, or may be arranged so that a part of the photographing light is branched and the branched light is received, or for AF (automatic focus adjustment). It may also serve as a measuring machine (luminance sensor) to be used.

  Although the present embodiment has been described with respect to an interchangeable lens, the present invention is not limited to this, and an imaging apparatus having an interchangeable lens (photographing lens) based on the above-described embodiment and an image sensor that receives photographing light from the interchangeable lens is also included. Applicable.

  In the above description, preferred embodiments of the present invention have been described. However, it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the present invention.

1 is a configuration diagram of Example 1. FIG. It is a process flowchart figure of Example 1. FIG. It is the data table example 1 of Example 1. FIG. 4 is a second example of a data table according to the first embodiment. FIG. 6 is a configuration diagram of Example 2. It is a process flowchart figure of Example 2. FIG. It is explanatory drawing of the linear approximation process in a table. It is explanatory drawing of the linear approximation process between several tables. FIG. 6 is a configuration diagram of Example 3. FIG. 10 is a processing flowchart of the third embodiment. FIG. 6 is a configuration diagram of Example 4. FIG. 10 is a processing flowchart of the fourth embodiment. FIG. 10 is a configuration diagram of Example 5. It is a comparison figure of distortion and magnification chromatic aberration. FIG. 10 is a process flowchart of the fifth embodiment. It is a graph of the relationship between camera characteristics and lateral chromatic aberration. It is a comparison figure of the spectral characteristics of various light sources. It is a graph of the relationship between a light source and a magnification chromatic aberration. FIG. 10 is a configuration diagram of Example 6. FIG. 10 is a processing flowchart of the sixth embodiment. FIG. 10 is a configuration diagram of Example 7. FIG. 10 is a process flowchart of the seventh embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Interchangeable lens 2 Focus lens 3 Zoom lens 4 Aperture 5 Extender lens 11 Focus position detection apparatus 12 Zoom position detection apparatus 13 Aperture position detection apparatus 14 Extender insertion / removal detection apparatus 20 Arithmetic circuit 21 Optical system parameter acquisition part 22 Camera main body identification part 23 Characteristic data reception unit 24 Sending type conversion unit 25 Correction data memory 26 Correction data transmission unit 31 SD / HD identification unit 42 2 → 1 byte conversion unit 43 Linear approximation processing unit 51 Mode identification unit 52 Mode switching device 61 Mode reception unit 71 Magnification Chromatic aberration extracting unit 81 Image capturing environment identifying unit 82 Image capturing environment setting device 83 Image capturing environment receiving unit 100 Camera body 101 Image sensor 102 Arithmetic circuit 103 Correction coordinate calculating unit 104 Correction data receiving unit 105 Data interpolation processing unit 106 Signal output means 107 Recording medium 108 Characteristic data transmission unit 109 Characteristic data memory 111 SD / HD memory 121 Mode transmission unit 122 Mode switching device 131 Luminance information acquisition unit 132 Color temperature calculation unit 133 Saturation region calculation unit 134 Imaging environment transmission unit

Claims (4)

An interchangeable lens that can be attached to and detached from the camera body,
A receiving unit for receiving information on the type of the camera body from the camera body;
A transmission unit that transmits aberration correction data including data relating to the amount of chromatic aberration of magnification based on the information received by the reception unit;
With
The aberration correction data is data used for image processing for reducing the influence of lateral chromatic aberration on an image captured by the camera body,
The transmission unit transmits different aberration correction data to the camera body according to information on the type of the camera body received by the reception unit.
An interchangeable lens characterized by that. The camera body is
A color separation optical system that separates photographing light received from the interchangeable lens into three color lights;
The interchangeable lens according to claim 1, further comprising three imaging elements corresponding to the three color lights.   The interchangeable lens according to claim 1, wherein the aberration correction data includes data relating to a distortion amount.   A camera apparatus comprising: the interchangeable lens according to claim 1; and a camera body including an image sensor that captures a subject image from the interchangeable lens.

Images